1. Field of the Invention
The present invention relates to a process-state management system configured to manage process-states of a plurality of production machines, which are adapted for a sequence of manufacturing processes configured to manufacture products, a management server and a control server adapted for the system, a method for managing the process-states, a method for manufacturing products using the method for managing the process-states, and a computer program product storing a program being executed on the management server so as to implement the method for managing the process-states.
2. Description of the Related Art
Semiconductor devices are fabricated using many expensive semiconductor production machines through a long sequence of manufacturing processes constituted by a complex combination of manufacturing processes such as, for example, lithography process, etching process, thermal treatment (oxidation, annealing, diffusion) process, ion implantation process, thin-film formation (CVD, sputtering, deposition) process, cleaning (removal of resist, cleaning using solution) process, and inspection process. Recently, large wafers such as a 300-mm diameter wafer have been particularly used. This causes increase in unit cost of wafers and increase in fabrication cost when fault occurs during a long sequence of manufacturing processes.
Therefore, for fabrication of semiconductor devices using many expensive semiconductor production machines, the effective operation rate of production machines inside and outside of a factory has been improved, and the performance thereof has been maintained or improved using an equipment engineering system (EES). “EES” denotes a computer system configured to acquire pieces of equipment information inherent in respective semiconductor production machines, statistically analyze data in the equipment information, and determine whether the respective semiconductor production machines operate normally or abnormally.
More specifically, a highly intelligent computer system has been constructed for managing a precise and correct operation and maintenance of individual production machines using advanced process control (APC) or a fault detection and classification (FDC) system. “APC” denotes a computer system configured to change a semiconductor fabrication process according to how a semiconductor production machine has processed wafers, more specifically, control a processing recipe by controlling a process number as a variable using multivariate model prediction and then providing feedback-control and feedforward-control in a process or between processes. Automated complex processing for semiconductor mass production allows APC technology to reduce production cost, improve production efficiency, consistently maintain high quality, and modify an arbitrary portion in a fabrication process in real time. It is expected that this technology achieves an improvement in profit per wafer and reduction in fabrication cost. In addition, “FDC” denotes a system configured to always monitor operation-states of semiconductor production machines and shut down various complex tools (semiconductor production machines) used for wafer fabrication before deviation in performance of a semiconductor production machine may adversely influence product yields. This achieves reduction in risk to wafers.
As described above, in the semiconductor device fabrication field, various computer technologies for reducing variation in performance of semiconductor production machines with the passage of time, for minimizing difference in film deposition among wafers, and for canceling difference in performance among semiconductor production machines, thereby providing a stable fabrication process have been developed. For example, a system configured to transfer data resulting from inspecting wafers during processing and after processing, record and manage a processed wafer log and a log of semiconductor production machines, carry out self-testing of each semiconductor production machines, and transmit appropriate commands has been proposed in the International Publication WO96/25760 (see line 25 on page 36 through line 2 on page 37.)
Meanwhile, with the earlier FDC systems, when monitoring many semiconductor production machines, data acquisition units (adapters) different for respective machine venders or for respective FDC box manufacturers are used to acquire independent pieces of information of respective semiconductor production machines and then carry out separate fault detection for them using computers (dedicated servers) different for the respective machine benders or for the respective FDC box manufacturers. Therefore, pieces of data regarding the earlier FDC are dispersed for the respective semiconductor production machines.
In other words, according to the earlier FDC architecture, fault detection methods and automatic fault analysis methods are different for the respective machine benders or for the respective FDC box manufacturers, and software programs (applications) used for automatic fault analysis are different for respective semiconductor production machines. Therefore, automatically analyzing applications for analyzing abnormalities of production machines are different from one another for respective semiconductor production machines, requiring additional investment.